No-Dig Watermain Cleaning and Lining Technology

Cities and water utilities around the world are required to provide reliable, safe drinking water to domestic, industrial and institutional consumers while meeting increasingly stringent regulatory requirements and customers’ expectations. Tuberculation and scale formation is a common problem in the old, rusty metallic water pipes that supply drinking water to our homes and businesses. These defects compromise hydraulic and structural integrity of water pipes and create water quality and safety issues. water main cleaning“This is like clogged arteries and blood vessels in our bodies which can cause increased blood pressure and cut off blood supply to heart causing heart attack,” says Dr. Mark Knight of uWaterloo’s Civil and Environmental Engineering. “Similarly, tuberculation, scale formation, and corrosion cause catastrophic pipeline failures.” Every year our cities lose millions of litres of drinking water through breaks and leaks causing damage to properties and lost revenue. The city of Toronto alone experiences 1,400 water pipe breaks every year requiring millions of dollars to fix broken pipes not to mention inconvenience to businesses, consumers and public. According to the US National Research Council of the National Academies, the municipal water supply systems span over 2 billion kilometers – about 72% of them are made up of metallic pipelines. Hundreds of billions of dollars are required to rehabilitate or replace these pipes.

The uWaterloo’s Centre for Advancement of Trenchless Technologies ( is at the forefront of finding timely and cost effective solutions for fixing drinking water pipelines’ issues. Dr. Mark Knight of Civil and Environmental Engineering, Dr. Rizwan Younis of the Centre for Advancement of Trenchless Technologies, and Dr. David Johnson of Mechanical and Mechatronics Engineering in collaboration Envirologics Engineering Inc. are working on the development of an innovative trenchless technology for the rehabilitation of aging drinking water pipelines.

The technology (Tomahawk System and Spray-on Polyurea Lining) can renew deteriorated water distribution networks with significant cost and time savings compared to the traditional open-cut pipe replacement methods. The cities will be able to rehabilitate drinking water pipelines at a fraction of replacement costs and without digging city streets. The technology will enable “same day” rehabilitation and return to service for water pipes compared to pipelines’ replacement using open-cut (excavating streets) method which takes months to complete. “We are very excited to be part of this initiative,” says Denise McGoldrick, Director of Water Services at the City of Waterloo. “This technology will allow the city to extend the life of iron water pipes at a lower cost than existing technologies with significantly lower disruption to our customers and traffic.”  Expected benefits to Canada include the creation of manufacturing and construction jobs while improving water quality for domestic, industrial and institutional consumers. Furthermore, tremendous savings in terms of social costs (avoiding construction related traffic delays or road closures, reduction in greenhouse gas emissions) can be accomplished.

The financial support from Envirologics Engineering Inc., NSERC (Natural Science and Engineering Research Council), and OCE (Ontario Centres of Excellence is greatly acknowledged.